I wasn’t aware that Office Communicator supported keyboard shortcuts for text formatting in the chat window.

Since I normally use RDP/MSTSC connections to a work machine (the laptop often moves around which means that network connections aren’t
“persistent”), which means that every once in a while a key like Shift, Alt, Ctrl, or Windows hangs.

That’s how I found out why sometimes the font in the chat window changed a bit: most often the font became strike through, which corresponds to Ctrl-T.

Three things that Microsoft should improve here:

Unlike the documentation, these shortcuts do not only hold for the “selected text”, but for any text you type after using the shortcut.

The context menu doesn’t include most of the entries (so there is no hint on that menu in which you can see them).

Even the context menu entry for Change Font does not include a hint that it maps to Ctrl+Shift+F.